MAGAZINE OF SCIENCE AND ART. 131 
CLASS REPT1LIA—ORDER OPIIIDIA, OR SERPENTS. 
FAMILY. 
A. INNOCUA, 
OR, 
HARMLESS SNARES, 
t. e. 
Snakes having no grooved tcetli in 
their upper jaw. 
b. VENENOSA. 
or, 
POISONOUS SNAKES. 
i. e. 
Snakes having certain teeth in their 
upper jaw grooved for the passage of 
poison. 
GENERA. 
SUPPOSED EXAMPLES IX 
AUSTRALIA. 
1. OPOTERODONTA. 
One or other of the jaws without any 
teeth. 
None known. 
2. AGLYPnODONTA. 
Teeth in both the upper and under jaws. 
Diamond Snake. 
3. OPISTHOGLYPHA. 
Posterior teeth of the upper jaw grooved in 
front. 
None known. 
4. PROTEROGLYPHA- 
- Anterior teeth of the upper jaw grooved in 
front. 
Black Snake? 
5. SOLENOGLYPHA. 
Death Adder ? 
Anterior teeth of the upper jaw offering two 
fangs, pierced by a veneniferous canal or tube.) 
In the mouth it is pierced deeply by numerous so- 
called innocent teeth, and the slime as well as 
saliva has thus the opportunity of penetrating into 
its structure. 
Without venturing to assert that the slime and 
saliva of the Boa possesses unusual digestive quali¬ 
ties, it is evident, first, that this serpent is provided 
with a sufficient means for overcoming its prey; 
and, secondly, that there is an especial secretion of 
fluid, with means for its transmission into the 
structure of the food. 
In the next genus, Opisthoglypha, no especial 
venom gland has been detected after careful dissec¬ 
tion. Thus Professor Owen, in his valuable work 
upon Odontology (page 225), states— 
“ Having been favoured by Dr. A. Smith witli 
specimens of the Bucepliallus Capcnsis, the results 
of my dissections are confirmatory of his own, as 
regards the absence of the poison apparatus in that 
snake; the ordinary salivary gland is large, espe¬ 
cially at its posterior part, which transmits its 
secretion by many pores, into the sheath of the 
grooved fangs; the presence of a distinct poison 
gland, directly communicating with the grooved 
posterior teeth, requires to be established, before 
the serpents with these teeth can he ranked with the 
poisonous genera/' 
Yet the posterior teeth, or fangs, are grooved, 
and, doubtless (as is surmised), for the transmission 
of an acrid saliva, which can only pass into the 
food after it has arrived at the back of the mouth, 
and must he considered as an adjunct to digestion, 
not as a life destroying agent. 
The last of the genera, Proteroglypha, includes 
all snakes possessing grooved tubular fangs in the 
superior maxillary bones, with or without a greater 
or less number of simple or grooved teeth. 
In some, we find a long maxillary bone, carrying 
the fang, and six or even eight teeth (Fig. 3, a. b.), 
in others, as in the rattlesnake, the entire denial 
development is centred in one long fang. 
In proportion to the number of the teeth is the 
diminished breadth and increased obliquity of the 
articulating surface of the superior maxillary bone, 
and the small size as well as inefficiency of the 
fang; from which, we may infer that in this genus 
the teeth carried by the superior maxillary bone 
act in concert, more or less powerfully, with the 
fang, and possess, with it, the function of inserting 
an acrid and poisonous fluid into the structure of 
the food, in accordance with the arrangement nature 
has adopted in genus Opisthoglypha. 
I shall, moreover, endeavour to prove that the 
primary object of the/uwg, in all varieties of this 
genus, is also adjunctive to digestion.—the second¬ 
ary, a means of killing prey, and the tertiary, a 
weapon of defence and offence. 
From these general facts, we gather that all 
toothed serpents possess an apparatus which secretes 
a fluid, possessing, in some, a simply digestive ac¬ 
tion, in others, more or less of an additional life 
destroying power; that the function of this secret 
tion is indicated by the individual dental apparatus, 
and finally, that the transition from the one to the 
other is gradual. 
In the innocent snake, (genus Aglyphodonta,) 
the up])er jaw possesses four rows of teeth, all of 
which are of a simple conical form, more or less 
curved backwards, and generally very slender. 
The upper jaw in the Opisthoglypha also pos¬ 
sesses four rows, but the posterior teeth in the 
superior maxillary bone are grooved. 
The upper jaw, in the Proteroglypha, possesses 
only two full row-s of teeth, viz., the palantine, or 
internal; while the superior maxillary bone carries 
at its anterior extremity a fang, larger or smaller, 
with or without a certain number of simple or 
grooved teeth posterior to it. 
The parts of the head, included in the venom 
apparatus, are as follows:— 
1st. The superior maxillary bone (Fig. 2, b), into 
which the fang and teeth are inserted. 
2nd. The fang (Fig. 2, a); with its mucous and 
aponeurotic enclosures. (Fig. 1, a. e .) 
3rd. The teeth. (Fig. 2, g.) 
4th. The pteregoid bone. (Fig. 2, c.) 
5th, The venom gland (Fig. 1,/.), with its duct. 
(Fig. 1, h.) 
6 th. The retractor muscle. (Fig. 1 and 2, d.) 
These I shall now describe. 
The superior maxillary hone itself (Fig. 3, 4, 5, 
8 ) consists of an anterior irregular body (Fig. 4, 
8 , c.), anti a posterior external ramus (Fig. 4, S, e .); 
the body is laterally convex, the convexity being 
greatest in the least venomous specimens; at the 
most anterior portion is a vertical ridge, on either 
